Refrigeration cycle equipment

Abstract

In multi-system air conditioners that include multiple refrigerant systems, comfort levels may be compromised in certain rooms when all indoor units within the same system are operating simultaneously. [Solution] The refrigeration cycle device 1 comprises a heat source side unit 2, a first user side unit group G1, a second user side unit group G2, and a control unit 3. The first user side unit group G1 includes at least a first user side unit U1. The total capacity of user side units U1 belonging to the first user side unit group G1 is less than the total capacity of user side units U2, U3, and U4 belonging to the second user side unit group G2. When changing from heating operation to defrosting operation, the control unit 3 sends a first instruction to user side unit U1 belonging to the first user side unit group G1, and sends a second instruction different from the first instruction to user side units U2, U3, and U4 belonging to the second user side unit group G2.

Description

Technical Field

[0001] It relates to a refrigeration cycle device.

Background Art

[0002] When performing a defrost operation, there has conventionally been a multi-type air conditioner that circulates refrigerant only in a specific indoor unit and does not circulate refrigerant in other indoor units (Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-147879)).

Summary of the Invention

Problems to be Solved by the Invention

[0003] In a multi-type air conditioner including a plurality of refrigerant systems, when all indoor units in the same system are operated, there is a problem that comfort may be impaired in a specific room.

Means for Solving the Problems

[0004] The refrigeration cycle device of the first aspect is a refrigeration cycle device including a heat source side unit, a first utilization side unit group, a second utilization side unit group, and a control unit. The first utilization side unit group includes at least a first utilization side unit. The total capacity of the utilization side units belonging to the first utilization side unit group is smaller than the total capacity of the utilization side units belonging to the second utilization side unit group. When changing from normal operation to abnormal operation, the control unit sends a first instruction to the utilization side units belonging to the first utilization side unit group and sends a second instruction different from the first instruction to the utilization side units belonging to the second utilization side unit group.

[0005] In this refrigeration cycle device, when changing from normal operation to abnormal operation, it is possible to suppress the impairment of comfort in the room where the utilization side units belonging to the first utilization side unit group are installed.

[0006] The refrigeration cycle apparatus of the second aspect is the refrigeration cycle apparatus of the first aspect, wherein the user-side unit has a user-side expansion valve. The first and second instructions include instructions relating to the opening degree of the user-side expansion valve. The opening degree of the user-side expansion valve in the first instruction is less than or zero than the opening degree of the user-side expansion valve in the second instruction.

[0007] This refrigeration cycle system allows for the control of the opening degree of the user-side expansion valve of a user-side unit belonging to a first user-side unit group, and the opening degree of the user-side expansion valve of a user-side unit belonging to a second user-side unit group.

[0008] The refrigeration cycle device in the third aspect is the refrigeration cycle device in the second aspect, wherein the heat source side unit comprises a compressor and a heat source side heat exchanger. Non-normal operation includes defrosting operation or thermo-off operation.

[0009] This refrigeration cycle system can perform defrosting or thermo-off operations as non-normal operations.

[0010] The refrigeration cycle device of the fourth perspective is a refrigeration cycle device of any of the first, third, or fourth perspectives, wherein the control unit has a setting unit. The setting unit causes the user to set user-side units belonging to one or more first user-side unit groups.

[0011] In this refrigeration cycle system, the user can configure the user-side units belonging to the first user-side unit group.

[0012] The refrigeration cycle device of the fifth aspect is the refrigeration cycle device of the fourth aspect, wherein the setting unit limits the total capacity of the user-side units belonging to the first user-side unit group.

[0013] In this refrigeration cycle system, non-normal operation can be performed in a short time by limiting the total capacity of the user units belonging to the first user unit group.

[0014] The refrigeration cycle device of the sixth aspect is the refrigeration cycle device of the third aspect, wherein the control unit closes the user-side expansion valve of the user-side unit belonging to the first user-side unit group during defrosting operation.

[0015] In this refrigeration cycle system, during defrosting operation, the temperature of the room in which the user-side unit belonging to the first user-side unit group is installed can be prevented by closing the user-side expansion valve of the user-side unit belonging to the first user-side unit group.

[0016] The refrigeration cycle device of the seventh aspect is the refrigeration cycle device of the third aspect, wherein the control unit closes the user-side expansion valve of the user-side unit belonging to the first user-side unit group when the thermo-off operation is in progress.

[0017] In this refrigeration cycle system, when the thermostat is turned off, the expansion valve on the user side of the user-side unit belonging to the first user-side unit group is closed, thereby maintaining a constant temperature in the room where the user-side unit belonging to the first user-side unit group is installed.

[0018] The refrigeration cycle device of the eighth aspect is the refrigeration cycle device of the seventh aspect, wherein the user-side unit has a user-side fan. The control unit stops the user-side fan of the user-side unit belonging to the first group of user-side units when the thermo-off operation is in progress.

[0019] In this refrigeration cycle system, when the thermo-off operation is performed, the user-side fan of the user-side unit belonging to the first user-side unit group is stopped, thereby maintaining a constant temperature in the room where the user-side unit belonging to the first user-side unit group is installed.

[0020] The refrigeration cycle device of the ninth aspect is the refrigeration cycle device of the third aspect, and normal operation includes heating operation. When the control unit changes from defrosting operation to heating operation, it makes the opening degree of the user-side expansion valve of the user-side unit belonging to the first user-side unit group greater than the opening degree of the user-side expansion valve of the user-side unit belonging to the second user-side unit group.

[0021] In this refrigeration cycle device, even when the temperature of the room in which the user-side unit belonging to the first user-side unit group is installed is decreasing during the defrost operation, the room in which the user-side unit belonging to the first user-side unit group is installed can be preferentially heated.

[0022] The refrigeration cycle device according to the tenth aspect is the refrigeration cycle device according to the fourth aspect or the fifth aspect, and the control unit includes a notification unit. The notification unit notifies the user of the demerits caused by setting the user-side unit belonging to the first user-side unit group.

[0023] In this refrigeration cycle device, it is possible to notify the user of the demerits that the time of abnormal operation becomes longer by setting the user-side unit belonging to the first user-side unit group.

[0024] The refrigeration cycle device according to the eleventh aspect is the refrigeration cycle device according to the fourth aspect or the fifth aspect, and the control unit includes a display unit. The display unit displays which user-side unit has been set as the user-side unit belonging to the first user-side unit group.

[0025] In this refrigeration cycle device, by displaying the setting of the user-side unit belonging to the first user-side unit group on the display unit, the user can be informed of the user-side unit belonging to the first user-side unit group.

[0026] The refrigeration cycle device according to the twelfth aspect is the refrigeration cycle device according to the fourth aspect or the fifth aspect, and the setting unit causes the user to set the user-side unit belonging to the first user-side unit group when the user satisfies a predetermined condition.

[0027] In this refrigeration cycle device, a user having a predetermined authority can be caused to set the user-side unit belonging to the first user-side unit group.

Brief Description of the Drawings

[0028] [Figure 1]This is a schematic configuration diagram of a refrigeration cycle apparatus according to the present embodiment. [Figure 2] This is a block diagram of a control device of a refrigeration cycle apparatus according to the present embodiment. [Figure 3] This is a flowchart showing a process when changing from a heating operation to a defrosting operation. [Figure 4] This is a flowchart showing a process when changing from a heating operation to a thermo-off operation.

Embodiments for Carrying Out the Invention

[0029] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0030] (1) Overall Configuration FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus 1 according to the present embodiment.

[0031] The refrigeration cycle apparatus 1 is an air conditioner that performs cooling / heating of a target space by performing a vapor compression type refrigerant cycle. The refrigeration cycle apparatus 1 performs normal operation and abnormal operation. The normal operation is the cooling operation and the heating operation of the refrigeration cycle apparatus 1. The abnormal operation is a defrosting operation or a thermo-off operation.

[0032] The refrigeration cycle apparatus 1 includes a heat source side unit 2, a first utilization side unit group G1, a second utilization side unit group G2, and a control device (control unit) 3. In other words, the refrigeration cycle apparatus 1 mainly includes one heat source side unit 2, a plurality of (four in this embodiment) utilization side units U1, U2, U3, U4 connected in parallel to this, a liquid refrigerant connection pipe 5, a gas refrigerant connection pipe 6, and a control device 3. The first utilization side unit group G1 includes at least a first utilization side unit. The liquid refrigerant connection pipe 5 and the gas refrigerant connection pipe 6 are pipes that connect the heat source side unit 2 and the utilization units U1, U2, U3, U4. The control device 3 controls the operations of various devices of the heat source side unit 2 and the utilization units U1, U2, U3, U4.

[0033] The refrigeration cycle device 1 is a multi-type system equipped with multiple user units U1 to U4 for a single heat source unit 2. In this embodiment, the capacity (horsepower) of user unit U1 is 2 horsepower, the capacity of user unit U2 is 3 horsepower, the capacity of user unit U3 is 12 horsepower, and the capacity of user unit U4 is 5 horsepower. The capacity of the user units is not limited to these.

[0034] In this embodiment, the refrigeration cycle device 1 has four user-side units, but the number of user-side units is not limited to four. The refrigeration cycle device 1 may have three or more user-side units. The refrigeration cycle device 1 may also have four or more user-side units.

[0035] The heat source unit 2 and the user units U1, U2, U3, and U4 are connected via liquid refrigerant connecting pipe 5 and gas refrigerant connecting pipe 6 to form a refrigerant circuit 10 through which the refrigerant circulates.

[0036] The refrigerant used in the refrigeration cycle device 1 is not limited to this, but could be, for example, R32.

[0037] The refrigeration cycle device 1 has two operating modes: a cooling operation mode for performing cooling operations and a heating operation mode for performing heating operations. In cooling operation, the refrigerant circulates in the refrigerant circuit 10 to realize a cooling cycle, thereby cooling the air in the target space where the user-side units U1, U2, U3, and U4 are installed. In heating operation, the refrigerant circulates in the refrigerant circuit 10 to realize a heating cycle, thereby heating the air in the target space where the user-side units U1, U2, U3, and U4 are installed.

[0038] The refrigeration cycle unit 1 performs cooling operation, heating operation, and defrosting operation. Defrosting operation is an operation in which the refrigerant is circulated in the same direction as the cooling cycle to melt the frost that has accumulated on the heat source side heat exchanger 23 (described later) of the heat source side unit 2.

[0039] (2) Detailed configuration (2-1) User Unit The user-side units U1, U2, U3, and U4 are units installed in the target space, such as inside a building. For example, user-side units U1, U2, U3, and U4 are ceiling-recessed units installed on the ceiling. However, user-side units U1, U2, U3, and U4 are not limited to ceiling-recessed units; they may also be ceiling-suspended units, wall-mounted units, or floor-standing units.

[0040] The user-side units U1, U2, U3, and U4 are each connected to the heat source unit 2 via liquid refrigerant connecting pipe 5 and gas refrigerant connecting pipe 6, respectively, and constitute part of the refrigerant circuit 10.

[0041] The user-side unit U1 includes a user-side refrigerant circuit 10a, a user-side fan 103, various sensors, and a user-side control unit 107.

[0042] The user-side refrigerant circuit 10a constitutes a part of the refrigerant circuit 10. The user-side refrigerant circuit 10a mainly comprises a user-side expansion valve 101 and a user-side heat exchanger 102.

[0043] The user-side fan 103 is driven by motor 103a.

[0044] The various sensors in the user-side unit U1 include a liquid-side temperature sensor 104, a gas-side temperature sensor 105, and a target space temperature sensor 106.

[0045] The user-side unit U2 includes a user-side refrigerant circuit 10b, a user-side fan 203, various sensors, and a user-side control unit 207.

[0046] The user-side refrigerant circuit 10b constitutes a part of the refrigerant circuit 10. The user-side refrigerant circuit 10b mainly comprises a user-side expansion valve 201 and a user-side heat exchanger 202.

[0047] The user-side fan 203 is driven by motor 203a.

[0048] The various sensors in the user-side unit U2 include a liquid-side temperature sensor 204, a gas-side temperature sensor 205, and a target space temperature sensor 206.

[0049] The user-side unit U3 includes a user-side refrigerant circuit 10c, a user-side fan 303, various sensors, and a user-side control unit 307.

[0050] The user-side refrigerant circuit 10c constitutes a part of the refrigerant circuit 10. The user-side refrigerant circuit 10c mainly comprises a user-side expansion valve 301 and a user-side heat exchanger 302.

[0051] The user-side fan 303 is driven by motor 303a.

[0052] The various sensors in the user-side unit U3 include a liquid-side temperature sensor 304, a gas-side temperature sensor 305, and a target space temperature sensor 306.

[0053] The user-side unit U4 includes a user-side refrigerant circuit 10d, a user-side fan 403, various sensors, and a user-side control unit 407.

[0054] The user-side refrigerant circuit 10d constitutes a part of the refrigerant circuit 10. The user-side refrigerant circuit 10d mainly comprises a user-side expansion valve 401 and a user-side heat exchanger 402.

[0055] The user-side fan 403 is driven by motor 403a.

[0056] The various sensors in the user-side unit U4 include a liquid-side temperature sensor 404, a gas-side temperature sensor 405, and a target space temperature sensor 406.

[0057] The configurations of the user-side units U2, U3, and U4 are the same as the corresponding configurations of the user-side unit U1. Therefore, below, only the configurations of the user-side unit U1 will be described, and the descriptions of the user-side units U2, U3, and U4 will be omitted unless specifically necessary.

[0058] (2-1-1) User-side heat exchanger The user-side heat exchanger 102 performs heat exchange between the refrigerant flowing inside the user-side heat exchanger 102 and the air in the target space passing over the surface of the user-side heat exchanger 102.

[0059] One end of the user-side heat exchanger 102 is connected to the liquid refrigerant connecting pipe 5 via refrigerant piping. The other end of the user-side heat exchanger 102 is connected to the gas refrigerant connecting pipe 6 via refrigerant piping.

[0060] The user-side heat exchanger 102 is not limited to a specific type, but for example, it is a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes (not shown) and a large number of fins (not shown).

[0061] The user-side heat exchanger 102 functions as an evaporator during cooling operation and defrosting operation. The user-side heat exchanger 102 functions as a condenser during heating operation.

[0062] (2-1-2) User-side expansion valve The user-side expansion valve 101 adjusts the pressure and flow rate of the refrigerant flowing through the user-side refrigerant circuit 10a. The user-side expansion valve 101 is installed in the refrigerant piping that connects the liquid side of the user-side heat exchanger 102 and the liquid refrigerant connecting pipe 5. The user-side expansion valve 101 is, for example, an electronically operated expansion valve with a variable opening.

[0063] (2-1-3) User-side fan The user-side fan 103 draws air from the target space into the user-side unit U1, supplies it to the user-side heat exchanger 102, and blows the air that has exchanged heat with the refrigerant in the user-side heat exchanger 102 back into the target space. The user-side fan 103 is, for example, a sirocco fan. However, the type of user-side fan 103 is not limited to a sirocco fan and can be selected as appropriate. The user-side fan 103 is driven by a motor 103a. The user-side fan 103 is a variable-speed fan driven by a motor 103a whose rotational speed can be changed.

[0064] (2-1-4) Sensor The user-side unit U1 has a liquid-side temperature sensor 104, a gas-side temperature sensor 105, and a target space temperature sensor 106 as sensors. The user-side unit U1 does not necessarily have to have all of the above sensors 104, 105, and 106; it may have only some of them.

[0065] The liquid-side temperature sensor 104 is installed in the refrigerant piping that connects the liquid side of the user-side heat exchanger 102 to the liquid refrigerant connecting pipe 5. The liquid-side temperature sensor 104 measures the temperature of the refrigerant flowing through the refrigerant piping on the liquid side of the user-side heat exchanger 102.

[0066] The gas-side temperature sensor 105 is installed in the refrigerant piping that connects the gas side of the user-side heat exchanger 102 to the gas-refrigerant communication pipe 6. The gas-side temperature sensor 105 measures the temperature of the refrigerant flowing through the refrigerant piping on the gas side of the user-side heat exchanger 102.

[0067] The target space temperature sensor 106 is installed on the intake side of the target space air of the user-side unit U1. The target space temperature sensor 46 detects the temperature of the target space air (target space temperature Tr) flowing into the user-side unit U1.

[0068] Although not limited to the type of sensor, in this embodiment, the liquid-side temperature sensor 104, the gas-side temperature sensor 105, and the target space temperature sensor 106 are thermistors.

[0069] (2-1-5) User-side control unit The user-side control unit 107 controls the operation of each part that constitutes the user-side unit U1.

[0070] The user-side control unit 107 is implemented by a microcomputer and memory, etc. The microcomputer comprises a control arithmetic unit and a memory device. A processor such as a CPU or GPU can be used for the control arithmetic unit. The control arithmetic unit reads a program stored in the memory device and performs predetermined arithmetic processing according to this program. Furthermore, the control arithmetic unit can write the calculation results to the memory device or read information stored in the memory device according to the program.

[0071] The user-side control unit 107 is electrically connected to the user-side expansion valve 101, user-side fan 103, liquid-side temperature sensor 104, gas-side temperature sensor 105, and target space temperature sensor 106 of the user-side unit U1 so as to enable the transmission and reception of control signals and information. Furthermore, the user-side control unit 107 is connected to the heat source-side control unit 37 (described later) of the heat source-side unit 2 via a transmission line 8a so as to enable the transmission and reception of control signals, etc. Note that the user-side control unit 107 and the heat source-side control unit 37 do not necessarily have to be connected by a physical transmission line. The user-side control unit 107 and the heat source-side control unit 37 may also be connected wirelessly for communication. The user-side control unit 107 is configured to receive various signals transmitted from a remote control (not shown) for operating the user-side unit U1. These various signals include signals related to the operation / stop of the user-side unit U1 and signals related to various settings. Signals related to various settings include, for example, the operating mode switching signal and the target temperature (set temperature Trs) for cooling and heating operations.

[0072] The user-side control unit 107 and the heat source-side control unit 37 work together to function as a control device 3. The functions of the control device 3 will be described later.

[0073] (2-2) Heat source side unit The heat source unit 2 is installed, for example, outside the building where the refrigeration cycle device 1 is installed.

[0074] The heat source unit 2 is connected to the user units U1, U2, U3, and U4 via the liquid refrigerant connecting pipe 5 and the gas refrigerant connecting pipe 6. The heat source unit 2, together with the user units U1, U2, U3, and U4, constitutes the refrigerant circuit 10.

[0075] The heat source unit 2 includes a heat source side refrigerant circuit 10e, a heat source side fan 28, various sensors, and a heat source side control unit 37.

[0076] The heat source side refrigerant circuit 10e constitutes a part of the refrigerant circuit 10. The heat source side refrigerant circuit 10e mainly includes a compressor 21, a four-way switching valve 22, a heat source side heat exchanger 23, a heat source side expansion valve 38, an accumulator 24, a liquid side shut-off valve 26, a gas side shut-off valve 27, an intake pipe 11a, a discharge pipe 11b, a first gas refrigerant pipe 11c, a liquid refrigerant pipe 11d, and a second gas refrigerant pipe 11e.

[0077] The suction pipe 11a connects the four-way switching valve 22 to the suction side of the compressor 21. An accumulator 24 is provided in the suction pipe 11a.

[0078] The discharge pipe 11b connects the discharge side of the compressor 21 to the four-way switching valve 22.

[0079] The first gas refrigerant pipe 11c connects the four-way switching valve 22 to the gas side of the heat source side heat exchanger 23.

[0080] The liquid refrigerant pipe 11d connects the liquid side of the heat source side heat exchanger 23 to the liquid refrigerant connecting pipe 5. The liquid refrigerant pipe 11d is equipped with a heat source side expansion valve 38. A liquid side shut-off valve 26 is provided at the connection point between the liquid refrigerant pipe 11d and the liquid refrigerant connecting pipe 5.

[0081] The second gas refrigerant pipe 11e connects the four-way switching valve 22 and the gas refrigerant connecting pipe 6. A gas-side shut-off valve 27 is provided at the connection point between the second gas refrigerant pipe 11e and the gas refrigerant connecting pipe 6.

[0082] The main components of the heat source unit 2 will be explained further below.

[0083] (2-2-1) Compressor The compressor 21 compresses the low-pressure refrigerant drawn in from the suction pipe 11a using a compression mechanism (not shown) and discharges it to the discharge pipe 11b. In this embodiment, the heat source unit 2 has only one compressor 21, but the number of compressors 21 is not limited to one. The heat source unit 2 may have multiple compressors 21 connected in parallel. Also, if the heat source unit 2 compresses the refrigerant in multiple stages, the heat source unit 2 may have multiple compressors 21 connected in series.

[0084] The compressor 21 is not limited to any particular type, but it is a positive displacement compressor such as a rotary or scroll type. The compression mechanism of the compressor 21 is driven by the motor 21a. The compression mechanism is driven by the motor 21a, which compresses the refrigerant. Here, the motor 21a is a motor whose rotational speed can be controlled by an inverter. The capacity of the compressor 21 is controlled by controlling the rotational speed (operating frequency) of the motor 21a.

[0085] (2-2-2) Four-way switching valve The four-way switching valve 22 switches the direction of refrigerant circulation by switching the direction of refrigerant flow.

[0086] During cooling and defrosting operations, the flow direction of the refrigerant discharged from the compressor 21 is switched by the four-way switching valve 22 to the connection state shown by the solid line in Figure 1. The four-way switching valve 22 connects the suction pipe 11a to the second gas refrigerant pipe 11e and the discharge pipe 11b to the first gas refrigerant pipe 11c (see the solid line in the four-way switching valve 22 in Figure 1). The refrigerant discharged from the compressor 21 flows through the refrigerant circuit 10 in the following order: heat source side heat exchanger 23, heat source side expansion valve 38, utilization side expansion valves 101, 201, 301, 401, utilization side heat exchangers 102, 202, 302, 402, and returns to the compressor 21. This realizes the cooling cycle.

[0087] During heating operation, the flow direction of the refrigerant discharged from the compressor 21 is switched by the four-way switching valve 22 to the connection state shown by the dashed line in Figure 1. The four-way switching valve 22 connects the suction pipe 11a to the first gas refrigerant pipe 11c and the discharge pipe 11b to the second gas refrigerant pipe 11e (see the dashed line in the four-way switching valve 22 in Figure 1). The refrigerant discharged from the compressor 21 flows through the refrigerant circuit 10 in the following order: user-side heat exchangers 102, 202, 302, 402, user-side expansion valves 101, 201, 301, 401, heat source-side expansion valve 38, heat source-side heat exchanger 23, and returns to the compressor 21. This realizes the heating cycle.

[0088] (2-2-3) Heat source side heat exchanger The heat source side heat exchanger 23 performs heat exchange between the refrigerant flowing inside the heat source side heat exchanger 23 and the air at the installation location of the heat source side unit 2 (referred to as heat source air) that passes over the surface of the heat source side heat exchanger 23. If the heat source side unit 2 is installed outdoors, the heat source side heat exchanger 23 performs heat exchange between the refrigerant flowing inside and the outdoor air.

[0089] One end of the heat source side heat exchanger 23 is connected to the liquid refrigerant pipe 11d. The other end of the heat source side heat exchanger 23 is connected to the first gas refrigerant pipe 11c.

[0090] The heat source side heat exchanger 23 is not limited to a specific type, but for example, it is a fin-and-tube type heat exchanger having heat transfer tubes (not shown) and a number of fins (not shown).

[0091] The heat source side heat exchanger 23 functions as an evaporator during heating operation. On the other hand, during cooling operation and defrosting operation, the heat source side heat exchanger 23 functions as a condenser (radiator).

[0092] (2-2-4) Heat source side expansion valve The heat source side expansion valve 38 is installed in the refrigerant circuit 10 between the heat source side heat exchanger 23 and the utilization side heat exchangers 42, 52, and 62. Specifically, the heat source side expansion valve 38 is installed in the liquid refrigerant pipe 11d between the heat source side heat exchanger 23 and the liquid side shut-off valve 26.

[0093] The heat source-side expansion valve 38 regulates the pressure and flow rate of the refrigerant flowing through the liquid refrigerant pipe 11d. The heat source-side expansion valve 38 is, for example, an electronically operated expansion valve with a variable opening.

[0094] (2-2-5) Accumulator The accumulator 24 separates the incoming refrigerant into gaseous refrigerant and liquid refrigerant. The accumulator 24 also has a function of storing excess refrigerant that is generated in response to fluctuations in the operating load of the user-side units U1, U2, U3, and U4. The accumulator 24 is installed in the suction pipe 11a. The refrigerant flowing into the accumulator 24 is collected in the upper space as gaseous refrigerant and in the lower space as liquid refrigerant. The gaseous refrigerant collected in the upper space flows out to the compressor 21.

[0095] (2-2-6) Liquid side shut-off valve and gas side shut-off valve The liquid-side shut-off valve 26 is a valve provided at the connection point between the liquid refrigerant pipe 11d and the liquid refrigerant connecting pipe 5. The gas-side shut-off valve 27 is a valve provided at the connection point between the second gas refrigerant pipe 11e and the gas refrigerant connecting pipe 6. The liquid-side shut-off valve 26 and the gas-side shut-off valve 27 are, for example, valves that are operated manually.

[0096] (2-2-7) Heat source side fan The heat source side fan 28 is a fan that draws in heat source air from outside the heat source side unit 2 into the heat source side unit 2 and supplies it to the heat source side heat exchanger 23, and discharges the air that has exchanged heat with the refrigerant in the heat source side heat exchanger 23 to the outside of the heat source side unit 2.

[0097] The heat source side fan 28 is, for example, a propeller fan. However, the type of fan for the heat source side fan 28 is not limited to a propeller fan and may be selected as appropriate.

[0098] The heat source side fan 28 is driven by motor 28a. While not limited to this, motor 28a is a motor whose rotational speed can be controlled by an inverter. The heat source side fan 28 is a fan with variable airflow, controlled by the rotational speed of motor 28a.

[0099] (2-2-8) Sensor The heat source unit 2 is equipped with various sensors. For example, the heat source unit 2 has the following temperature sensor and pressure sensor. The types of temperature and pressure sensors can be selected as appropriate.

[0100] The sensors in the heat source unit 2 include an intake pressure sensor 29, a discharge pressure sensor 30, an intake temperature sensor 31, a discharge temperature sensor 32, and a heat exchanger temperature sensor 33. The heat source unit 2 does not necessarily have to have all of the sensors 29-33 described above; it may have only some of them. Furthermore, the heat source unit 2 may have sensors other than those described above.

[0101] The suction pressure sensor 29 is installed in the suction pipe 11a. The suction pressure sensor 29 is a sensor that measures the suction pressure Ps. The suction pressure Ps is the low-pressure value of the refrigerant cycle.

[0102] The discharge pressure sensor 30 is installed in the discharge pipe 11b. The discharge pressure sensor 30 is a sensor that measures the discharge pressure Pd. The discharge pressure Pd is the high-pressure value of the refrigerant cycle.

[0103] The intake temperature sensor 31 is installed in the intake pipe 11a. The intake temperature sensor 31 is a sensor that measures the intake temperature Ts.

[0104] The discharge temperature sensor 32 is installed in the discharge pipe 11b. The discharge temperature sensor 32 is a sensor that measures the discharge temperature Td.

[0105] The heat exchanger temperature sensor 33 is installed in the heat source side heat exchanger 23. The heat exchanger temperature sensor 33 measures the temperature of the refrigerant flowing through the heat source side heat exchanger 23. During cooling operation, the heat exchanger temperature sensor 33 measures the refrigerant temperature corresponding to the condensation temperature Tc, and during heating operation, it measures the refrigerant temperature corresponding to the evaporation temperature Te.

[0106] (2-2-9) Heat source side control unit The heat source side control unit 37 controls the operation of each part that constitutes the heat source side unit 2.

[0107] The heat source side control unit 37 is implemented by a microcomputer and memory, etc. The microcomputer comprises a control arithmetic unit and a memory device. A processor such as a CPU or GPU can be used for the control arithmetic unit. The control arithmetic unit reads a program stored in the memory device and performs predetermined arithmetic processing according to this program. Furthermore, the control arithmetic unit can write the calculation results to the memory device or read information stored in the memory device according to the program.

[0108] The heat source side control unit 37 is electrically connected to the heat source side unit 2, specifically the compressor 21, four-way switching valve 22, heat source side expansion mechanism 38, heat source side fan 28, suction pressure sensor 29, discharge pressure sensor 30, suction temperature sensor 31, discharge temperature sensor 32, and heat exchanger temperature sensor 33, to enable the transmission and reception of control signals and information. Furthermore, the heat source side control unit 37 is connected to the user side control units 107, 207, 307, and 407 of the user side units U1, U2, U3, and U4 via a transmission line 8a to enable the transmission and reception of control signals and other information.

[0109] The heat source side control unit 37 and the user side control units 107, 207, 307, and 407 of the user side units U1, U2, U3, and U4 work together to function as a control device 3 that controls the operation of the refrigeration cycle device 1. The functions of the control device 3 will be described later.

[0110] (2-3) Refrigerant connecting piping The refrigeration cycle unit 1 includes a liquid refrigerant connecting pipe 5 and a gas refrigerant connecting pipe 6 as refrigerant connecting pipes. The liquid refrigerant connecting pipe 5 and the gas refrigerant connecting pipe 6 are pipes that are installed at the installation site of the refrigeration cycle unit 1 when the refrigeration cycle unit 1 is installed. Various lengths and diameters of pipes are used for the liquid refrigerant connecting pipe 5 and the gas refrigerant connecting pipe 6 depending on the installation conditions such as the installation site and the combination of the heat source side unit and the user side unit.

[0111] The user-side refrigerant circuits 10a, 10b, 10c, and 10d of user-side units U1, U2, U3, and U4, and the heat source-side refrigerant circuit 10e of heat source-side unit 2 are connected by liquid refrigerant connecting pipe 5 and gas refrigerant connecting pipe 6, thereby forming the refrigerant circuit 10 of the refrigeration cycle device 1.

[0112] (2-4) Control device Figure 2 is a block diagram of the control unit (control unit) 3. The control unit 3 is configured such that the heat source side control unit 37 of the heat source side unit 2 and the user side control units 107, 207, 307, and 407 of the user side units U1, U2, U3, and U4 are connected via a transmission line 8a to enable the transmission and reception of control signals and the like. The control unit 3 is realized when the microcomputers of the heat source side control unit 37 and the user side control units 107, 207, 307, and 407 execute programs stored in memory.

[0113] It should be noted that the control device 3 in this embodiment is merely one example. Functions similar to those performed by the control device 3 may be realized by hardware such as logic circuits, or by a combination of hardware and software.

[0114] Furthermore, while the control device 3 is configured with the heat source side control unit 37 and the user side control units 107, 207, 307, and 407, it is not limited to this configuration. For example, the refrigeration cycle device 1 may have, in addition to the heat source side control unit 37 and the user side control units 107, 207, 307, and 407, or instead of the heat source side control unit 37 and the user side control units 107, 207, 307, and 407, a control device provided separately from the heat source side unit 2 and user side units U1, U2, U3, and U4 that implement some or all of the functions of the control unit 3 described below.

[0115] Furthermore, the control device 3 of the refrigeration cycle device 1 does not necessarily have to have some or all of the functions described below. For example, some or all of the functions of the control device 3 described below may be implemented by a central controller or the like installed in a location separate from the refrigeration cycle device 1. In other words, the functions of the control device 3 do not have to be performed solely by the refrigeration cycle device 1, and may be implemented by a central controller or the like (not shown) installed separately from the refrigeration cycle device 1. Also, the central controller and the heat source side control unit 37 of the heat source side unit 2 may control the user side expansion valves 101, 102, 301, 401, etc. of the user side units U1, U2, U3, U4.

[0116] As shown in Figure 2, the control device 3 is connected to the heat source side unit 2, which includes user-side expansion valves 101, 201, 301, 401, compressor 21, four-way switching valve 22, heat source side expansion valve 38, user-side fans 103, 203, 303, 403, and heat source side fan 28, and the user-side units U1, U2, U3, U4, enabling it to send and receive control signals and the like. Furthermore, as shown in Figure 2, the control unit 3 is connected to the liquid-side temperature sensors 104, 204, 304, 404, gas-side temperature sensors 105, 205, 305, 405, target space temperature sensors 106, 206, 306, 406, suction pressure sensor 29, discharge pressure sensor 30, suction temperature sensor 31, discharge temperature sensor 32, and heat exchanger temperature sensor 33, enabling it to send and receive control signals and the like.

[0117] When the control device 3 changes from normal operation to abnormal operation, it sends a first instruction to the user units belonging to the first user unit group G1 and a second instruction, different from the first instruction, to the user units belonging to the second user unit group G2.

[0118] The first and second instructions include instructions regarding the opening degrees of the user-side expansion valves 101, 201, 301, and 401. The opening degree of the user-side expansion valve in the first instruction is less than or zero than the opening degree of the user-side expansion valve in the second instruction.

[0119] When the control device 3 changes from defrosting operation to heating operation, it increases the opening degree of the user-side expansion valve of the user-side unit belonging to the first user-side unit group G1 compared to the opening degree of the user-side expansion valve of the user-side unit belonging to the second user-side unit group G2. If user-side unit U1 is a user-side unit belonging to the first user-side unit group G1, and user-side units U2, U3, and U4 are user-side units belonging to the second user-side unit group G2, the control device 3 sends a first instruction to user-side unit U1 belonging to the first user-side unit group and a second instruction to user-side units U2, U3, and U4 belonging to the second user-side unit group when changing from defrosting operation to heating operation. The control device 3 increases the opening degree of the user-side expansion valve 101 of user-side unit U1 belonging to the first user-side unit group G1 compared to the opening degrees of the user-side expansion valves 201, 301, and 401 of user-side units U2, U3, and U4 belonging to the second user-side unit group G2.

[0120] The control device 3 mainly comprises a setting unit 12a and a storage unit 12b as its functional units.

[0121] (2-4-1) Settings section The setting unit 12a causes the user to set up user units belonging to one or more first user unit groups G1. In this embodiment, the setting unit 12a causes the user to set up user unit U1 as a user unit belonging to the first user unit group G1 (first user unit). At this time, user units U2, U3, and U4 are set up as the second user unit group G2. It is assumed that user unit U1 belonging to the first user unit group G1 is installed in a different room from user units U2, U3, and U4 belonging to the second user unit group G2. User units U2, U3, and U4 belonging to the second user unit group G2 may be installed in different rooms, or they may be installed in the same room.

[0122] Note that the user unit belonging to the first user unit group G1 is not limited to user unit U1. The setting unit 12a may also cause the user to set any of user units U1 to U4 as a user unit belonging to the first user unit group G1, in order of the earliest setting timing.

[0123] The setting unit 12a limits the total capacity of user units belonging to the first user unit group G1. The total capacity of user units belonging to the first user unit group G1 is less than the total capacity of user units belonging to the second user unit group G2. The setting unit 12a limits the capacity of user unit U1 belonging to the first user unit group G1 so that the total capacity of user unit U1 belonging to the first user unit group G1 is less than half the total capacity of user units U1 to U4 of the refrigeration cycle device 1.

[0124] In this embodiment, the total capacity of user unit U1 belonging to the first user unit group G1 is 2 horsepower, and the total capacity of user units U2, U3, and U4 belonging to the second user unit group G2 is 20 horsepower. Therefore, the total capacity of user unit U1 belonging to the first user unit group G1 is smaller than the total capacity of user units U2, U3, and U4 belonging to the second user unit group G2. Also, the total capacity of user unit U1 belonging to the first user unit group G1 is 2 horsepower, which is 11 horsepower, half the total capacity of user units U1 to U4 of the refrigeration cycle device 1. Therefore, the total capacity of user unit U1 belonging to the first user unit group G1 is smaller than half the total capacity of user units U1 to U4 of the refrigeration cycle device 1. In other words, the combined capacity of user units U2, U3, and U4 belonging to the second user unit group G2 is 20 horsepower, and the combined capacity of user units U1 to U4 of the refrigeration cycle device 1 is 11 horsepower. Therefore, the combined capacity of user units U2, U3, and U4 belonging to the second user unit group G2 is greater than half the combined capacity of user units U1 to U4 of the refrigeration cycle device 1. When defrosting is performed using half the total capacity of the user-side units U1 to U4 of the refrigeration cycle device 1, compared to when defrosting is performed using the entire total capacity of the user-side units U1 to U4 of the refrigeration cycle device 1, the amount of heat obtained by the user-side units will be less. However, since the compressor 21 accounts for the majority of the heat generated during defrosting, there will be no significant difference in the amount of heat obtained by the user-side units. (2-4-2) Storage section The memory unit 12b stores which user-side unit of the refrigeration cycle device 1 is set as a user-side unit belonging to the first user-side unit group G1. In this embodiment, it stores that user-side unit U1 is set as a user-side unit belonging to the first user-side unit group G1.

[0125] (3) Operation of the refrigeration cycle The operation of the refrigeration cycle unit 1 during cooling, heating, and defrosting operations will be described below.

[0126] (3-1) Cooling operation When the remote control instructs the refrigeration cycle unit 1 to perform cooling operation, the control device 3 sets the operating mode of the refrigeration cycle unit 1 to the cooling operation mode. When the predetermined conditions for starting cooling operation are met in the cooling operation mode, the four-way switching valve 22 is switched to the cooling operation state (the state shown by the solid line of the four-way switching valve 22 in Figure 1), and the compressor 21, heat source side fan 28, and user side fans 43, 53, and 63 are operated to start cooling operation.

[0127] In the refrigerant circuit 10, the low-pressure gaseous refrigerant in the refrigerant cycle is drawn into the compressor 21, where it is compressed to become the high-pressure gaseous refrigerant in the refrigerant cycle. The high-pressure gaseous refrigerant is sent to the heat source side heat exchanger 23 via the four-way switching valve 22, where it exchanges heat with the heat source air supplied by the heat source side fan 28 and condenses to become the high-pressure liquid refrigerant.

[0128] The high-pressure liquid refrigerant flows through the liquid refrigerant pipe 11d and passes through the heat source side expansion valve 38. The high-pressure liquid refrigerant is sent to the user side units U1, U2, U3, and U4 via the liquid refrigerant connecting pipe 5. The high-pressure liquid refrigerant sent to user side units U1, U2, U3, and U4 is reduced in pressure to near the suction pressure of the compressor 21 at the user side expansion valves 101, 201, 301, and 401, becoming a gas-liquid two-phase refrigerant and sent to the user side heat exchangers 102, 202, 302, and 402.

[0129] The gaseous two-phase refrigerant evaporates in the user-side heat exchangers 102, 202, 302, and 402, where it exchanges heat with the air in the target space supplied to the user-side heat exchangers 102, 202, 302, and 402 by the user-side fans 103, 203, 303, and 403, becoming a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant is sent to the heat source-side unit 2 via the gaseous refrigerant communication pipe 6 and flows into the accumulator 24 via the four-way switching valve 22. The low-pressure gaseous refrigerant that flows into the accumulator 24 is then drawn back into the compressor 21.

[0130] (3-2) Heating operation When the remote control instructs the refrigeration cycle unit 1 to perform heating operation, the control device 3 sets the operating mode of the refrigeration cycle unit 1 to heating operation mode. When the predetermined heating operation start conditions are met in heating operation mode, the four-way switching valve 22 is switched to the heating operation state (the state shown by the dashed line on the four-way switching valve 22 in Figure 1), and heating operation is started by operating the compressor 21, the heat source side fan 28, and the user side fans 103, 203, 303, and 403.

[0131] In the refrigerant circuit 10, the low-pressure gaseous refrigerant in the refrigerant cycle is drawn into the compressor 21, where it is compressed to become the high-pressure gaseous refrigerant in the refrigerant cycle. The high-pressure gaseous refrigerant is sent to the user-side heat exchangers 102, 202, 302, and 402 via the four-way switching valve 22, where it exchanges heat with the air in the target space supplied by the user-side fans 103, 203, 303, and 403, condenses, and becomes the high-pressure liquid refrigerant.

[0132] The high-pressure liquid refrigerant is reduced in pressure as it passes through the user-side expansion valves 101, 201, 301, and 401. The refrigerant reduced in pressure at the user-side expansion valves 101, 201, 301, and 401 is sent to the heat source-side unit 2 via the liquid refrigerant connecting pipe 5 and flows into the liquid refrigerant pipe 11d. The refrigerant flowing through the liquid refrigerant pipe 11d is reduced in pressure to near the suction pressure of the compressor 21 as it passes through the heat source-side expansion valve 38, becoming a gas-liquid two-phase refrigerant and sent to the heat source-side heat exchanger 23.

[0133] The two-phase gaseous refrigerant evaporates in the heat source side heat exchanger 23 through heat exchange with the heat source air supplied to the heat source side heat exchanger 23 by the heat source side fan 28, becoming a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant flows into the accumulator 24 via the four-way switching valve 22. The low-pressure gaseous refrigerant that flows into the accumulator 24 is then drawn back into the compressor 21.

[0134] (3) Defrosting operation The control device 3 performs defrosting when the operating mode of the refrigeration cycle unit 1 is in heating operation mode. When the control device 3 determines that the predetermined defrosting start conditions have been met while the operating mode of the refrigeration cycle unit 1 is in heating operation mode and heating operation is being performed, it switches the four-way switching valve 22 to the connection state shown by the solid line in Figure 1, thereby switching the operating state of the refrigeration cycle unit 1 to defrosting operation.

[0135] The defrosting start condition is a condition under which it is desirable to defrost the heat source side heat exchanger 23. For example, the control device 3 determines that the defrosting start condition has been met when the refrigerant temperature measured by the heat exchanger temperature sensor 33 falls below a predetermined temperature. The predetermined temperature is, for example, -5°C. Alternatively, the control device 3 may determine that the defrosting start condition has been met when the duration of heating operation exceeds a predetermined time.

[0136] In the refrigerant circuit 10, the low-pressure gaseous refrigerant in the refrigerant cycle is drawn into the compressor 21, where it is compressed to become the high-pressure gaseous refrigerant in the refrigerant cycle. The high-pressure gaseous refrigerant is sent to the heat source side heat exchanger 23 via the four-way switching valve 22, where it exchanges heat with the heat source air supplied by the heat source side fan 28 and condenses to become the high-pressure liquid refrigerant. In defrosting operation, the high-temperature, high-pressure gaseous refrigerant is sent to the heat source side heat exchanger 23 to melt the frost that has accumulated on the heat source side heat exchanger 23.

[0137] The high-pressure liquid refrigerant flows through the liquid refrigerant pipe 11d and passes through the heat source side expansion valve 38. The high-pressure liquid refrigerant is sent to the user side units U1, U2, U3, and U4 via the liquid refrigerant connecting pipe 5. The high-pressure liquid refrigerant sent to user side units U1, U2, U3, and U4 is reduced in pressure to near the suction pressure of the compressor 21 at the user side expansion valves 101, 201, 301, and 401, becoming a gas-liquid two-phase refrigerant and sent to the user side heat exchangers 102, 202, 302, and 402.

[0138] The gaseous two-phase refrigerant evaporates in the user-side heat exchangers 102, 202, 302, and 402, where it exchanges heat with the air in the target space supplied to the user-side heat exchangers 102, 202, 302, and 402 by the user-side fans 103, 203, 303, and 403, becoming a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant is sent to the heat source-side unit 2 via the gaseous refrigerant communication pipe 6 and flows into the accumulator 24 via the four-way switching valve 22. The low-pressure gaseous refrigerant that flows into the accumulator 24 is then drawn back into the compressor 21.

[0139] When the control device 3 determines that the defrosting termination conditions have been met during defrosting operation, it decides to terminate the defrosting operation and returns to heating operation. For example, the control device 3 determines that the defrosting termination conditions have been met when the refrigerant temperature measured by the heat exchanger temperature sensor 33 reaches or exceeds a predetermined termination judgment temperature and this condition continues for a predetermined time or longer. However, the defrosting termination conditions are not limited to the above conditions. For example, the control device 3 may immediately determine that the defrosting termination conditions have been met when the refrigerant temperature measured by the heat exchanger temperature sensor 33 reaches or exceeds a predetermined termination judgment temperature.

[0140] (4) Procedure when changing from heating operation to defrosting operation Figure 3 is a flowchart showing the process when switching from heating operation to defrosting operation.

[0141] In step S1, the user units belonging to the first user unit group G1 are set. In this embodiment, the setting unit 12a causes the user to set user unit U1, one of the user units U1 to U4 of the refrigeration cycle device 1, as a user unit belonging to the first user unit group G1. At this time, user units U2 to U4 are set as user units belonging to the second user unit group G2. The total capacity of user unit U1 belonging to the first user unit group G1 is 2 horsepower, and the total capacity of user units belonging to the second user unit group G2 is 20 horsepower. Therefore, the total capacity of user unit U1 belonging to the first user unit group G1 is smaller than the total capacity of user units belonging to the second user unit group G2.

[0142] Furthermore, the setting unit 12a limits the capacity of user-side units U1 belonging to the first user-side unit group G1 so that the total capacity of user-side units U1 belonging to the first user-side unit group G1 is less than half the total capacity of user-side units U1 to U4 of the refrigeration cycle device 1. In this embodiment, the total capacity of user-side units U1 belonging to the first user-side unit group G1 is 2 horsepower, which is less than 11 horsepower, which is half the total capacity of user-side units U1 to U4 of the refrigeration cycle device 1.

[0143] In step S2, the heating operation is started. In this embodiment, the remote control is used to instruct the user to start the heating operation.

[0144] In step S3, the operation is changed from heating to defrosting. In this embodiment, the control device 3 determines that the defrosting start condition has been met when the refrigerant temperature measured by the heat exchanger temperature sensor 33 falls below a predetermined temperature, and changes from heating to defrosting.

[0145] In step S4, the user-side expansion valve of the user-side unit belonging to the first user-side unit group G1 is controlled. In this embodiment, the control device 3 closes the user-side expansion valve 101 of the user-side unit U1 belonging to the first user-side unit group G1 during defrosting operation. As a result, refrigerant does not flow to the user-side heat exchanger 102 of the user-side unit U1 belonging to the first user-side unit group G1, so that the temperature of the room in which the user-side unit U1 is installed does not decrease during defrosting operation.

[0146] On the other hand, the user-side expansion valves 201, 301, and 401 of user-side units U2 to U4, which belong to the second user-side unit group G2, are open. Therefore, refrigerant flows through the user-side heat exchangers 202, 302, and 402 of user-side units U2 to U4, which belong to the second user-side unit group G2.

[0147] In step S5, the defrosting operation is terminated. In this embodiment, when the refrigerant temperature measured by the heat exchanger temperature sensor 33 reaches a predetermined termination judgment temperature or higher, the control device 3 determines that the defrosting termination condition has been met, terminates the defrosting operation, and switches to heating operation.

[0148] (5) Characteristics (5-1) The refrigeration cycle device 1 according to this embodiment comprises a heat source side unit 2, a first user side unit group G1, a second user side unit group G2, and a control unit 3. The first user side unit group G1 includes at least one user side unit U1. The total capacity of the user side units U1 belonging to the first user side unit group G1 is less than the total capacity of the user side units U2, U3, and U4 belonging to the second user side unit group G2. When changing from heating operation to defrosting operation, the control unit 3 sends a first instruction to the user side unit U1 belonging to the first user side unit group G1, and sends a second instruction different from the first instruction to the user side units U2, U3, and U4 belonging to the second user side unit group G2.

[0149] Traditionally, during defrosting operations, it was necessary to circulate cold refrigerant to indoor units (user units) installed in specific rooms, such as the president's office. However, instructions to the expansion valve of the user unit could only be given as a single, unified instruction based on the operating conditions.

[0150] In the refrigeration cycle device 1 of this embodiment, the heat source unit 2 can issue instructions to each user unit U1 to U4. For example, during defrosting, it is possible to individually control the user units U1 to U4 by closing the expansion valve to prevent refrigerant flow to a specific room that has been set in advance. This prevents temperature drops in specific rooms.

[0151] In this refrigeration cycle device 1, when switching from heating operation to defrosting operation, it is possible to suppress the loss of comfort in the room where the user unit U1 belonging to the first user unit group G1 is installed.

[0152] (5-2) In the refrigeration cycle device 1 according to this embodiment, the user-side units U1 to U4 have user-side expansion valves 101, 201, 301, and 401. The first and second instructions include instructions relating to the opening degree of the user-side expansion valves 101, 201, 301, and 401. The opening degree of user-side expansion valve 101 in the first instruction is less than or zero than the opening degree of user-side expansion valves 201, 301, and 401 in the second instruction.

[0153] In this refrigeration cycle device 1, the opening degree of the user-side expansion valve 101 of user-side unit U1 belonging to the first user-side unit group G1, and the opening degrees of the user-side expansion valves 201, 301, and 401 of user-side units U2, U3, and U4 belonging to the second user-side unit group G2 can be controlled, respectively.

[0154] (5-3) In the refrigeration cycle device 1 according to this embodiment, the heat source side unit 2 includes a compressor 21 and a heat source side heat exchanger 23. Non-normal operation includes defrosting operation.

[0155] This refrigeration cycle device 1 can perform defrosting as an irregular operation.

[0156] (5-4) In the refrigeration cycle device 1 according to this embodiment, the control unit 3 has a setting unit 12b. The setting unit 12b causes the user to set the user-side unit U1 as a user-side unit belonging to the first user-side unit group G1.

[0157] In this refrigeration cycle device 1, the user can configure the user-side units belonging to the first user-side unit group G1.

[0158] (5-5) In the refrigeration cycle device 1 according to this embodiment, the setting unit 12b limits the total capacity of the user-side units U1 belonging to the first user-side unit group G1.

[0159] In this refrigeration cycle device 1, defrosting can be performed in a short time by limiting the total capacity of the user-side units U1 belonging to the first user-side unit group G1.

[0160] (5-6) In the refrigeration cycle device 1 according to this embodiment, the control unit 3 closes the user-side expansion valve 101 of the user-side unit U1 belonging to the first user-side unit group G1 during defrosting operation.

[0161] In this refrigeration cycle device 1, during defrosting operation, the temperature of the room in which the user-side unit U1 belonging to the first user-side unit group G1 is installed can be prevented by closing the user-side expansion valve 101 of the user-side unit U1 belonging to the first user-side unit group G1.

[0162] (6) Variant (6-1) Variation 1A In this embodiment, the case where the abnormal operation is a defrosting operation has been described, but the abnormal operation may also be a thermo-off operation, and the system may change from heating operation to thermo-off operation.

[0163] The control device 3 can switch the state of the user-side unit (e.g., user-side unit U1) between a thermo-on state and a thermo-off state based on the degree of deviation between the set temperature set by the user of the user-side unit via remote control and the air temperature in the space where the user-side unit is installed (target space temperature). The thermo-on state means that the refrigerant is flowing through the user-side heat exchanger (e.g., user-side heat exchanger 102) and sufficient heat exchange is taking place between the refrigerant and the indoor air. The thermo-off state means that the refrigerant is not flowing through the user-side heat exchanger and there is virtually no heat exchange taking place between the refrigerant and the indoor air.

[0164] When the control device 3 determines that the thermo-off start condition has been met, it switches the state of the user unit from the thermo-on state to the thermo-off state, thereby changing from heating operation to thermo-off operation.

[0165] Figure 4 is a flowchart showing the process when changing from heating operation to thermo-off operation. Step S1, which sets the user-side unit belonging to the first user-side unit group G1, and step S2, which performs heating operation, are the same as the process in this embodiment shown in Figure 3, so a detailed explanation is omitted.

[0166] In step S11, the operation is changed from heating operation to thermo-off operation. The control device 3 determines that the thermo-off start condition has been met when, for example, the target space temperature Tr of the room where the user unit U1 belonging to the first user unit group G1 is installed, as measured by the target space temperature sensor 106, reaches the set temperature Trs set by the user via the remote control, and a predetermined time has elapsed, and switches the state of the user unit U1 to the thermo-off state.

[0167] In step S12, the opening degree of the user-side expansion valve is controlled. When the thermostat is turned off, the control device 3 closes the user-side expansion valve 101 of the user-side unit U1 belonging to the first user-side unit group G1. The control device 3 may also stop the user-side fan 103 of the user-side unit U1 belonging to the first user-side unit group G1 when the thermostat is turned off.

[0168] In step S13, the thermo-off operation is terminated. When the target space temperature Tr measured by the target space temperature sensor 106 falls below a predetermined temperature below the set temperature Trs, the control device 3 determines that the thermo-off termination condition has been met and switches the state of the user unit U1 to the thermo-on state, thereby terminating the thermo-off operation and switching to heating operation.

[0169] In Modification 1A, by closing the user-side expansion valve 101 of the user-side unit U1 belonging to the first user-side unit group G1 during thermo-off operation, the temperature of the room in which the user-side unit U1 belonging to the first user-side unit group G1 is installed can be kept constant. Also, in Modification 1A, by stopping the user-side fan 103 of the user-side unit U1 belonging to the first user-side unit group G1 during thermo-off operation, the temperature of the room in which the user-side unit U1 belonging to the first user-side unit group G1 is installed can be kept constant.

[0170] (6-2) Variation 1B When the control device 3 changes from defrosting operation to heating operation, it may set the opening degree of the user-side expansion valve 101 of user-side unit U1 belonging to the first user-side unit group G1 to be greater than the opening degrees of the user-side expansion valves 201, 301, and 401 of user-side units U2, U3, and U4 belonging to the second user-side unit group G2.

[0171] In modified example 1B, even if the temperature of the room where the user unit U1 belonging to the first user unit group G1 is installed decreases during defrosting operation, the room where the user unit U1 belonging to the first user unit group G1 is installed can be preferentially heated.

[0172] (6-3) Modification 1C The control device 3 may also have a notification unit. The notification unit notifies the user of the disadvantages of setting user unit U1 belonging to the first user unit group G1. For example, the notification unit notifies the user of the disadvantage that setting user unit U1 belonging to the first user unit group will result in a longer defrosting operation. In this case, the control device 3 may control the user fans 203, 303, and 403 of user units U2, U3, and U4 belonging to the second user unit group G2 to increase their rotation speed.

[0173] In modification 1C, by setting user unit U1 to belong to the first user unit group, the user can be notified of the disadvantage of prolonged abnormal operation.

[0174] (6-4) Modification 1D The control device 3 may have a display unit. For example, the central controller may have a display unit. The display unit shows which of the user-side units U1 to U4 of the refrigeration cycle device 1 has been set as a user-side unit belonging to the first user-side unit group G1.

[0175] In the modified example 1D, the settings of the user units belonging to the first user unit group G1 are displayed on the display unit, thereby informing the user of the user units belonging to the first user unit group G1.

[0176] (6-5) Modification 1E The configuration unit 12a may configure the user to configure a user unit belonging to the first user unit group when the user meets predetermined conditions. For example, the configuration unit 12a may configure a user with configuration authority to configure a user unit belonging to the first user unit group G1.

[0177] In the modified example 1E, a user with certain privileges can be allowed to configure a user unit belonging to the first user unit group G1.

[0178] (6-6) Modification 1F There may be multiple user units belonging to the first user unit group G1.

[0179] For example, in the refrigeration cycle device 1 shown in Figure 1, the setting unit 12a causes the user to set user units U1 and U2 as user units belonging to the first user unit group G1. At this time, user units U3 and U4 are set as user units belonging to the second user unit group G2. The combined capacity of user units U1 and U2 belonging to the first user unit group G1 is 5 horsepower, which is less than the combined capacity of user unit groups G3 and G4 belonging to the second user unit group G2, which is 17 horsepower.

[0180] Furthermore, the combined capacity of user units U1 and U2 is 5 horsepower, which is less than half of the combined capacity of user units U1 to U4, which is 22 horsepower (11 horsepower). The combined capacity of the second user unit group G2 is 17 horsepower, which is greater than half of the combined capacity of user units U1 to U4, which is 22 horsepower (11 horsepower). Therefore, even when user units U1 and U2 are set to the first user unit group G1, abnormal operation can be performed in a short time.

[0181] Furthermore, the combined capacity of user units U1, U2, and U3 is 17 horsepower, which is greater than the combined capacity of user unit U4, which is 5 horsepower. Therefore, the setting unit 12a can prevent the user from setting user units U1, U2, and U3 as user units belonging to the first user unit group G1, thereby preventing a prolonged period of abnormal operation.

[0182] (6-7) While embodiments of this disclosure have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of this disclosure as described in the claims. [Explanation of Symbols]

[0183] 1. Refrigeration cycle system 2 Heat source side unit 3. Control device (control unit) G1 First user-side unit group G2 Second user-side unit group U1~U4 User Units 12a Setting section 21 Compressor 23 Heat source side heat exchanger 24 Accumulators 29. Intake pressure sensor 30 Discharge pressure sensor 31. Intake temperature sensor 32 Discharge temperature sensor 33 Heat exchanger temperature sensor 101, 201, 301, 401 User-side expansion valve 102, 202, 302, 402 User side heat exchanger 103, 203, 303, 403 User-side fans 104, 204, 304, 404 Liquid-side temperature sensor 105, 205, 305, 405 Gas-side temperature sensor 106, 206, 306, 406 Target space temperature sensor [Prior art documents] [Patent Documents]

[0184] [Patent Document 1] Japanese Patent Publication No. 2002-147879

Claims

1. Heat source side unit (2), A first group of user units (G1) including at least a first user unit, The second group of user-side units (G2), Control unit (3) and A refrigeration cycle device comprising, The total capacity of the user-side unit (U1) belonging to the first user-side unit group is less than the total capacity of the user-side units (U2, U3, U4) belonging to the second user-side unit group. When the control unit changes from normal operation to abnormal operation, it sends a first instruction to the user-side unit belonging to the first user-side unit group, and sends a second instruction different from the first instruction to the user-side unit belonging to the second user-side unit group. Refrigeration cycle device (1).

2. The user-side unit has user-side expansion valves (101, 201, 301, 401), The first and second instructions include instructions relating to the opening degree of the user-side expansion valve, The opening degree of the user-side expansion valve in the first instruction is less than or zero than the opening degree of the user-side expansion valve in the second instruction. The refrigeration cycle apparatus according to claim 1.

3. The heat source side unit comprises a compressor (21) and a heat source side heat exchanger (23). The aforementioned non-normal operation includes defrosting operation or thermo-off operation. The refrigeration cycle apparatus according to claim 2.

4. The control unit has a setting unit (12a) that causes the user to set one or more user units belonging to the first user unit group. A refrigeration cycle apparatus according to any one of claims 1 to 3.

5. The setting unit limits the total capacity of the user units belonging to the first user unit group. The refrigeration cycle apparatus according to claim 4.

6. The control unit closes the user-side expansion valve of the user-side unit belonging to the first user-side unit group during the defrosting operation. The refrigeration cycle apparatus according to claim 3.

7. The control unit closes the user-side expansion valve of the user-side unit belonging to the first user-side unit group when the thermo-off operation is performed. The refrigeration cycle apparatus according to claim 3.

8. The user-side unit has user-side fans (103, 203, 303, 403), The control unit stops the user-side fan of the user-side unit belonging to the first user-side unit group when the thermo-off operation is performed. The refrigeration cycle apparatus according to claim 7.

9. The aforementioned normal operation includes heating operation, When the control unit changes from the defrosting operation to the heating operation, it makes the opening of the user-side expansion valve of the user-side unit belonging to the first user-side unit group greater than the opening of the user-side expansion valve of the user-side unit belonging to the second user-side unit group. The refrigeration cycle apparatus according to claim 3.

10. The control unit includes a notification unit that notifies the user of the disadvantages of setting the user unit belonging to the first user unit group. The refrigeration cycle apparatus according to claim 4.

11. The control unit has a display unit, The display unit indicates which of the user-side units has been set as the user-side unit belonging to the first group of user-side units. The refrigeration cycle apparatus according to claim 4.

12. The setting unit, when the user meets predetermined conditions, causes the user to set the user unit belonging to the first user unit group. The refrigeration cycle apparatus according to claim 4.

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